Greenman D L, Highman B, Kodell R L, Schieferstein G J, Norvell M
Food Chem Toxicol. 1985 Jan;23(1):73-8. doi: 10.1016/0278-6915(85)90223-6.
C3H/HeN-MTV+ female mice were fed diets containing targeted concentrations of 320 or 640 ppb diethylstilboestrol (DES) starting at 3, 5, 7 or 11 wk of age and continuing throughout their remaining lifespan. Mice were housed in either a single-corridor conventional animal room or in a double-corridor barrier-type animal room. Mice housed in the conventional animal room and started on DES at 7 or 11 week of age developed palpable mammary tumours somewhat sooner than the corresponding groups of mice kept in the barrier animal room. In mice housed in the barrier animal room and exposed to a given DES concentration, there was very little difference between mice started on DES at 3, 5 or 7 wk of age in the exposure time required for the development of palpable mammary tumours. There was a striking difference, however, between mice started on DES at 7 wk and those started at 11 wk of age in the exposure time needed before mammary tumours appeared. Mice started at 11 wk of age developed tumours with, on average, about 4 wk less exposure than did those started at 7 wk. This suggests that treatment between 7 and 11 wk of age had little or no effect on mammary tumour development. In conclusion, both animal-room environment and age at the start of DES treatment influenced the mammary tumour response in female C3H/HeN-MTV+ mice.
将320或640 ppb己烯雌酚（DES）的目标浓度添加到饮食中，从3、5、7或11周龄开始喂养C3H/HeN-MTV+雌性小鼠，并持续到它们的剩余寿命。小鼠饲养在单通道常规动物房或双通道屏障式动物房中。饲养在常规动物房且7或11周龄开始使用DES的小鼠比饲养在屏障动物房中的相应小鼠组更早出现可触及的乳腺肿瘤。在饲养在屏障动物房且暴露于给定DES浓度的小鼠中，3、5或7周龄开始使用DES的小鼠在出现可触及乳腺肿瘤所需的暴露时间上差异很小。然而，7周龄开始使用DES的小鼠与11周龄开始使用DES的小鼠在乳腺肿瘤出现前所需的暴露时间上存在显著差异。11周龄开始使用DES的小鼠发生肿瘤的平均暴露时间比7周龄开始使用DES的小鼠少约4周。这表明7至11周龄的处理对乳腺肿瘤的发生几乎没有影响。总之，动物房环境和DES处理开始时的年龄都会影响雌性C3H/HeN-MTV+小鼠的乳腺肿瘤反应。
